Rotary pump or blower



March 5, 1929. E, J, WENDELL 1,704,642

ROTARY PUMP OR BLOWER Filed Nov. 30, 1926 Patented Mar. 5, 1929. i

nvnnr :ri WENDELL, or WAYNE, retirasezriviriiia,`

ROTARY rUMr' oncsnovvna Application'led Novemberf), 1926.. Serialo. 151,771.

This invention relatos to rotary pumps of Vthe type including geared er intermeshing rotors, and relates more particularly to-improvements in the methods of driving such pumps.

The principal object of the invention is to provide an improved drive or transmission Y particularly well suited for use in connection with high speed electric motors, and to this end the invention contemplates the provi-l sion of a compact drive or transmission affording a desirable relatively great speed re-y duction between the motor and the pump.

A further object of the invention is to provide a drive for pumps of the stated type in which the normal wear of the parts will not affect the timing or set relation between they intermeshing rotors. Y

A still further object of the invention is to provide means whereby the timing of the rotors may be effected through the drive .or transmission mechanism by simple adpistment of one or more ofthe parts, whereby the necessity for close machining and mounting-of the shafts and rotors in the pump and of the transmission elementsis obviated. A.

These and other useful ends hereinafter appearing l have accomplished by means of the mecha-nismllustrated in the attached drawings, in which:

Figure lis a plan view of a pumpmade'in accordance with the present invention, and

Fig. 2 is a section on the line 2 2, Fig. 1.

Referring to the drawings, and particularly to Figs. 1 and 2 thereof, it will be noted that the pump in the embodiment illustrated comprises a casing 1 having an intake opening 2 and a discharge opening 8, and having-mountl ed in the interior thereof intermeshing rotors Cil 4, 4. These rotors are mounted, respectively, on shafts 5 and 6, which extend throughone side of the casing, as shown in F ig. 2, and have mounted on their projecting ends spiral gears 7 and 8 which mesh with a multiple-thread worm 9 journaled directly between the gears, as clearly shown. In the present instance, the shaft 6 is threaded-on its outer end for the reception of lock nuts 1l and 12 which occupy positions one on either side of the gear 8 and provide means for adjusting the gear axially of the shaft tothereby vary the position of thc gear With respect tothe relatively fixed worm 9. v

It will be noted that by reason o-f the character of the intermeshing rotors 4, 4, there isa definite relation between the rotors, the spiral gears 7 and 8, and the worm 9 requiringv an ao curate relative setting. of these parts. Normail f this involves a? careful mounting of the gears on the shafts and .careful adjust-ment of the worm 9, and entails accurate machining of the parts. l*lt will be apparent, however, that with the gears relatively fixed 'circumferenl tially of the shafts and meshing with the worm, movement longitudinaily'of the shaftof one of said gears must result in a rotative ad-l `iustment of the corresponding shaft and a consequent relative adjustment of the rotors. rlhe relative positioning and adjustment of the rotors and of theassociated parts may therefore be accomplished by the axial adjust- Vment of the gear 8, made possible by use of the :nutsll land 12 for retaining the gear laxially vof the shaft.l

Entirely aside from the adjustment feature described above with its many obvious advantages, the drivefor transmission mechanismk including the gears 7 and 8 and the intermediate worm 9 meshing with both gears affords` material and peculiar advantages V'in connecs tion with rotors ofthe type described.V It has been customary to gear the intermeshing rotors of the pumps together by means of spur gears and to drive both rotors through vone o f these gears or through a second gearon one-of the rotor shafts. It is frequently desirable to operate small sized pumps from electric motors, which later operate ata much higher' rate of speed than themaximumefficient rotor speed of the pump. Where, the pumps therefore are coupled direct to the Vmotors, through spur gear drive, the pump speed is necessarily excessive. Speed lreduction with spur gears is impractical by reason of the excessive spacel which. such reduction gearing occupies. The worm and spiral gear transmission `described above provides ay wide yrange of speed ratios between the motor and the pump with aminimum of bulk inthe drive or transmission mechanism. Y

A further important advantage of the drive resides in the fact that Wear developing in the transmission mechanism between the worm and the gears is equally distributed .between the parts and does not affect the rotor ll() l over the customary spur gear transiiiission in pumps of this type, and aords also the great manufacturing advantage or" making possible t-lie propersetting or timing of the rotorsV and of the driving part-s by meansot a simple adJustment of one ot the gears axially of j Y its shaft.

I ain aware that this type of transmission y is not in its'elil novel, and no attempt is herein made to claim this per se. iid/Thot l do believe v is novel is the combination oit' the hei-einli a pump of the stated type' with the attendant ur poot-eil 'advantages oi" sustained eiiicie oy and durability, due to a constant-ly maintained relalira rotary pump, the combination with pair of intermeshing rotors, of shafts snpportingjthe said rotors, a gear Carried by each ot' said shafts, a. worin mounted. between and meshing with both of said gears, at least one of said gears being spiralin character, and

means `providing' loi' adjustment oit said spiral gear longitudinally ot its shaft.

nviinr J. WENDELL, 

